This invention relates to chemical treatment of liquid in circulating systems and, more particularly, to an improved water treatment device, specifically a chlorinator, for use with swimming pool filtration and circulation systems.
In the chlorination of swimming pool water, it is known to provide either addition of fixed quantities of chlorine-producing chemicals directly to swimming pool water, as by directly pouring the liquid or dry materials to the water, or to use devices for time-release discharge of such chemicals.
Time-discharge release has been carried out by using either floating devices or chemical feeders wherein water is caused to flow through a containment of chemical to be dissolved. Such floating devices permit chlorine-releasing substance to leach from a container into water surrounding the device. These floating devices, sometime facetiously called "Rubber Duck" devices, may be objectional to users because an undesirable "cloud" of undispersed released chemical surrounds the device as it floats.
In use of such chemical feeders, a known type of device has a container through which water pumped by a swimming pool filtration and circulation system for purposes of dissolving treatment chemical in the container.
Chlorination chemicals or other chemical compositions for treatment of swimming pool water, such as calcium hypochlorite and various other chemicals are available in the form of a concentrated cake, pellet or tablet wherein the active ingredients are held by a matrix of inert materials. The matrix breaks down when exposed to water, causing dissolution and entrainment of the substance held in a container.
Heretofore, it has been the practice to locate such devices on the pump discharge side of the circulation system, i.e., in a location within the circulation system such that water will flow from the pump outlet, as by means of a bypass, through the container, for flow into the stream of water delivered to the pool. In some types of installations, water exposed to the chemical will not pass through the pool filter, so that particulate matter resulting from dissolution of the matrix containing the active chemical may produce particles which flow back into the pool. There, they may constitute an objectionable source of contamination, producing cloudiness or eventually settling to the bottom of the pool from which they must be vacuumed or once again drawn into the pool circulation inlet for ultimate filtration.
Although it may be known alternatively to connect conventional chemical containers in a flow path by which the water with entrained treatment chemical necessarily will flow through the pool filter, such chemical containers and their associated plumbing are specialized items which require installation involving cutting, splicing and connection of various pump flow lines to and from the chemical feeder. Therefore, such prior art chemical feeders are to a degree objectionably expensive or cumbersome as well as time-consuming to install and service.